I'll try to nail a bunch of questions in one post:
1. Never use a task killer. You will eat your battery much more monitoring the usage with killer than this task manager. Task manager alerts you when your RAM usage is a bit high and you can auto-end apps that would normally use a lot of RAM if allowed to run in the background, thus eating battery. I put a bunch of apps on auto-end but I'm skeptical as to whether it's working. What you need is Watchdog. It will tell you what apps are using too much CPU, which will truly slow down your phone. There is a free Lite version in the Market.
2. Always use LauncherPro. The end.
3. I've yet to meet an Android phone that doesn't warm up to some capacity when being used for more than 10 mins in whatever form or fashion you are using it. If you're worried, you can download an internal temp gauge that will tell you what the battery's temp is. But what good will that do since you don't want to do anything to cool it down besides not use the phone for a minute.
4. Download a freeware called Audio Profile Manager. You can only load 3 profiles in the free version, but I have mine set to a sleep setting where it only rings at night, no notifications. The difference with Audio Profile is you can tell it to SPECIFICALLY vibrate for texts ONLY. I'm sure there's other ones like it. You can also set one to do all vibrate, but why would you do that when there should be a toggle widget that allows you to set it to vibrate only. If not, hit the sleep button on top, hit it again, slide the arrow on the right to the left and you're in vibrate.
5. I am a previous BB user. I loved my BB. But Android was so much more appealing. And now that this phone is out, BB has a run for their money.
6. If you want a good camera on a cell phone, go buy a camera, not a phone. But this one does fine for those not in photography classes or professional shooting.
7. No one asked about this, but ROOT THIS PHONE! There are instructions at the top about doing so. Why??? You can get rid of Sprint's crappy bloatware that is killing some of your RAM/battery/CPU. Also, you can have a free WiFi Tether, which I personally don't care about. And rooting won't cause you to lose anything you currently have. You can just delete the junk. Even if that's all you do, do it.
Bottom line, after coming from the Samsung Transform, this is a FANTASTIC phone. I've had a few issues where it will lock up and reboot itself, but I'm finding that I don't care because it reboots in under 30 seconds. And I'm rarely doing anything important when it does. Now that I've rooted, hopefully I will have less of those issues.
The end. Have a happy day/2 years now that you own this phone.